As semiconductor technology evolves, decreasing transistor sizes call for an ever higher degree of accuracy, repeatability and cleanliness in wafer processes and process equipment. Fierce competition within the semiconductor industry calls for ever lower cost per processed wafer. All of these requirements apply generally to all of the processing equipment used in the fabrication sequence.
Among the various types of equipment that exists for semiconductor processing is equipment that involves the use of plasmas, such as plasma etch, plasma-enhanced chemical vapor deposition (PECVD) and resist strip equipment. The types of equipment required for these processes include components which are located within the plasma chamber, and must function in that environment. The environment inside the plasma chamber may include exposure to the plasma and to etchant gasses, and materials used for such components are preferably adapted to withstand the environmental conditions in the chamber.
Generally, replacement of such components is expensive, and component lifetime as measured by the total number of wafers processed before replacement is needed is typically the denominator in the cost determination. Components with lifetimes that are considered low are therefore considered expensive and alternative solutions are generally sought. Conversely, methods which extend the lifetime of component parts are considered to lower their cost.